Composición fenólica y actividad antioxidante de las hojas de Psidium friedrichsthalianum(O. Berg) Nied.

Introduction: medicinal plants are an important antioxidizers source. Objective: to determinate the phenolic composition and the antioxidant activity from extracts of Psidium friedrichsthalianum (O.Berg) Nied´s leaves. Method: an experimental preclinical study was developed to evaluate from the toxicological and pharmacologic point of view, extracts of Psidium friedrichsthalianum's leaves. It was qualitativety examinated the chemical composition of metanolic extract and in ethyl acetate; the contents of phenols, flavonoids and tannins was determined. The antioxidant activity was evaluated in vitro by the essays: kidnap of the radical DPPH, antirust capability total, quelante activity, reductor power/ferric antioxidant and ferric tiocianatos´s method. It was evaluated the ex vivo antioxidant activity by the lipidic peroxidation in Wistar rats. Results: phenols, flavonoids and tannins were the main metabolites identified. The metanolic extract shows the bigger value of phenols and flavonoids. The extracts show antioxidant activity in vitro , being the metanolicone the best. The ex vivo evaluation of the extract shows decreased malonildialdehido's concentrations, and inhibition of the lipidic peroxidation to all the dose studied, with a dose dependent behaviour. Conclusions: Metanolic Psidium friedrichsthalianum's extract shows antioxidant activity in vitro and ex vivo in relation with his phenolic compounds.